Boat davit



W. C. DEAN June 30, 1936.

BOAT DAVIT Filed Sept. 20, `1934 FIG. l

INVENTOR VV. C. De a n ATTORNEY Patented .une 30, 1936 UNITED STATESPATENT OFFICE BOAT DAVIT Walter C. Dean, Chevy Chase, Md. ApplicationSeptember 20, 1934, Serial No. 744,811 3 Claims. (Cl. 9-22) (Grantedunder the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) This invention relates to a davitor the like wherein the fall of the hoisting line is likely to be swungagainst a portion of the davit structure and has for its object toprovide means to prevent chang of the rope when the fall is drawn acrossthe davit in frictional contact therewith.

In the drawing:

Fig. 1 is a side elevational view of the present invention showing theposition of the fall when the boat is suspended outboard and showing indotted lines the relations of the several parts after the boat has beenswung inboard;

Fig. 2 is a detail View, with parts in section, of my improved davit.

Rotating boat davits usually chafe the rope fall when the davit is swunginto certain positions since the rope must wrap partially around thevertical shaft of the davit. This also causes increased friction whichadds to the effort required in hoisting the boat. My improved daviteliminates both of these objectionable results.

In Fig. 1 theshaft 3 of the davit is rotatably mounted in a suitablesupport 4. 'I'he upper portion 5 carries the usual tackle 6 from whichthe fall 'I passes to a winch or snatch block 8 adjacent the foot of thedavit. It is apparent that when the davit is swung outboard, as shown infull lines in Fig. 1, the fall 1 is brought into frictional contact withthe davit, since the block 8 must be so positioned as to permit ofswinging the davit to the full inboard position and must not be sospaced from the davit longitudinally of the ship that it exerts a foreand aft component of pull on the davit.

Around the shaft of the davit and extending over such length thereof asmight possibly be contacted by the fall 1 I dispose a sleeve 9 whereofthe thrust due to weight is taken by antifriction bearings I0 disposedin a groove II in collar I2 that is fixed to the davit shaft and has anupwardly extending inner flange I3 overlapping the lower end of sleeve9. Lower antifriction bearings I4 and upper antifriction bearings I5 aredisposed between the sleeve 9 and the davit I0 to insure maximum ease ofrotation of the sleeve 9. y

Fittings I6 for pressure lubrication of the bearings are preferablyprovided. It is apparent that when the fall 1 moves across the sleeve 9in frictional contact therewith the sleeve will rotate freely and. thuswill prevent chang of the rope and also eliminate the frictionaladdition to the load in hoisting that is inevitably present when the oldstructure of davit is used.

While my invention has been shown and described as embodied in a boatdavit for purposes of setting forth the novel features thereof, it isobvious that its usefulness is not limited to the particular casementioned but is susceptible of application to numerous uses of likenature.

The invention described herein may be manufactured and used by or forthe Government ofA the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

I claim:

1. The combination with a davit mounted at one end with its long axisvertical to rotate for swinging an object transversely past its axis,hoisting tackle on said davit at the other end thereof, and a rotatableelement fixed adjacent the said one end with a fall of said tacklepassing to said element, of a collar fixed on said davit, said collarhaving a longitudinally extending peripheral ange and an annular grooveadjacent the base of said ange that forms a race for antifrictionbearing elements, a sleeve disposed around said davit over the majorportion of the length of the shaft of the davit, antifriction elementsin said groove disposed to support the thrust of said sleeve, andantifriction bearings in said sleeve adjacent the ends thereof betweensaid sleeve and the davit.

2. The combination with a davit mounted at one end with its long axisvertical to rotate for swinging an object transversely past its axis,hoisting tackle on said davit at the other end thereof, and a rotatableelement fixed adjacent the said one end with a fall of said tacklepassing to said element, of a sleeve disposed around said davit over themajor portion of the length of the shaft of the davit, antifrictionbearings between said sleeve and the davit, a collar xed on said davitand having a flange extending over one end of said sleeve, andantifriction bearings between said collar and said sleeve to take thethrust of said sleeve.

3. The combination with a davit mounted at one end with its long axisvertical to rotate for swinging an object transversely past its axis,hoisting tackle on said davit at the other end thereof, and a rotatableelement fixed adjacent the said one end with a fall of said tacklepassing to said element, of a collar fixed on said davit, said collarhaving a longitudinally extending peripheral flange, and a sleeverotatable independently of the shaft of said davit disposed around saidshaft over the major portion of the length of said shaft with one end ofsaid sleeve disposed within said peripheral flange.

WALTER C. DEAN.

